300 Win Mag loads...

stovepipe · Posted: Tue Jun 22, 2010 6:54 am Post subject: Re: 300 Win Mag loads...

Scope- resnugged half way through first load.

Collet die- yes. No runout that I could detect. I aint talking large groups, I'm talking no groups...not sure if the case prep had anything to do with it. They all looked really good.

Powder- not that it may matter but this was not SC.
67gr was START. So- that's where I started. I've got nothing to loose 'cept pride so it's back to the drawing board. I just might not have enough powder to zip that zuchinni sized bullet up to stable speed- least that's my guess. 72gr is max so...I might go up .25gr atta time and stop at 69.5gr or 70gr. then go to a smaller bullet and start over.

slimjim · Posted: Tue Jun 22, 2010 10:34 am Post subject: Re: 300 Win Mag loads...

Wow, stovepipe, what a day!! Disappointing reload performance then traffic snarls!!!

I had a windage screw begin to fail on a Leupold scope base and watched the impacts start walking across the target about 6 inches. When I checked the screw for tightness, the head came off after a 1/4 turn.

Some recommendations.
1. Make sure the mounts are secure.
2. Was all the brass the the same? You said they were Federal but just checking because it took me a while to realize the I couldn't get a load to group when the brass was mixed.
3. It takes several shots to know that a load is good but only 2 shots to know a load has no promise. That's why I only load 3 of each recipe when I'm first starting out to develop a load.

When first trying a powder for a case as large as a 300 Win Mag, I load in 1 grain increments (3 rounds) skipping the high pressure side and usually the low side also. I use 0.0 or 0.5 depending what best covers the min to max range. From this data, I judge where the sweet spot is and load at that poweder weight and 0.5 above and below. I load 3 or 5 rounds each depending on how many bullets I have left. I can usually get a reasonably accurate load going in less than 25 rounds.

I think you should try again with a larger spread of powder weights. Though your initial results are varied enough to make me think there may be something else amiss. I do well with the Lee Classic hand loaders for my .270 and .308 but my .223 results have been disappointing in my AR. After hearing your experience, it makes me think there just might be something off in the loader. Even though I use a their hand loader, I never use a hammer. I use my vice to size the neck and my drill press to seat primers and bullets.

slimjim · Posted: Tue Jun 22, 2010 11:01 am Post subject: Re: 300 Win Mag loads...

stovepipe wrote:

I might go up .25gr atta time and stop at 69.5gr or 70gr. then go to a smaller bullet and start over.

Somehow I missed your post before mine. I must not have refreshed my screen. I wouldn't be shy about approaching the max if you do it sensibly. I have only been getting pressure signs on my light bullets at max in my .270. My heavier bullets are not showing pressure signs at the max. I usually find my more accurate loads near the max and seems to correlate with a full case.

When I step up to the next powder weight, I inspect that first case out of the chamber. Flatten a bit on the edge of the primer is a sign you are building pressure but not necessarily over. If the firing pin dimble has a ridge on the edge that you finger nail can catch on, you are propably over the pressure you should be at. One caution, I've found Federal cases to have less volume (heavier) than other cases which causes higher pressures. In my .308, the Federal cases could fit the max loads in them and get the bullet to the proper seating depth.

If you don't want to risk loading rounds that you will have to pull the bullets out of, load up to 71 gr then one round at 71.5 fire just for a pressure check. If that looks ok, load one at 72.0 and check it.

stovepipe · Posted: Tue Jun 22, 2010 11:04 am Post subject: Re: 300 Win Mag loads...

Thanks fer the input. I think my pride was a little dented more than anything. Embarassed

My OCW, optimum barrel time, etc. has not yet been realised, obivously. Wink

Yep- brass was all the same lot etc.
I loc-tited, again, the cross bolt(s) for the ring base, gonna load up some more and keep plugging away. Since I had the scope off last night gonna rezero at 50y a couple shots then go from there. I'm no where near MAX yet and the pressure signs were OK so... back to the drawing board, I got plenty of bullets, powder etc. I'll nail it. Stay tuned. Very Happy

stovepipe · Posted: Tue Jun 22, 2010 1:51 pm Post subject: Re: 300 Win Mag loads...

Sierra wrote me back....super service!

Gave me some suggestions to try. Sent me a PDF for an accuracy load too using RE22. Not H4831...

They did have one listed for H4831 SC, not regular like I have.
Not sure if there's a burn rate diff or not. But max recomended there was 68.6gr.

70gr max for IMR 4831.

My OAL was on.
They also suggested trying to sneak up on the lands more too (Chambered?).

Glad I got this info before proceeding. They also want to hear back from me as I progress.
Great customer service!

Good stuff....

stovepipe · Posted: Tue Jun 22, 2010 4:35 pm Post subject: Re: 300 Win Mag loads...

Stuck a bullet in a fired case, slowly closed the bolt, checked it twice.
3.518 OAL
3.340 is Rec. MAX (for mag feeding). Pretty big jump, no?

There's plenty of bearing surface in the neck seated .010" off the lands so..might try a few like that and go back in increments of .010" to try and find a sweet spot with the H4831, as suggested, till I can get some RE22.
63.6 is START
68.6gr is their MAX recomended w/ H4831.
Way less than other data for a "Jacketed Bullet".
Glad I got this new data before I upped the load.
Pressure is OK @ 68gr, still some radius on the primer left, bolt opens freely. Don't think I'd want more pressure than this though. It's safe but... Maybe I can make it work with the 4831, maybe not. We shall see.
Seems seating close to the lands make's a big diff as a few have suggested same. Learning lots, hope to find out what this cannon likes, someday.

Stay tuned.....

slimjim · Posted: Tue Jun 22, 2010 9:37 pm Post subject: Re: 300 Win Mag loads...

I check your bullet stability. With a length of 1.393 inches for the 200gr SMK, you have more than enough twist to stabilize your bullet even at 2000 fps at the muzzle. (Oops, had to fix a typo. Darn those significant figure.)

stovepipe · Posted: Thu Jul 08, 2010 12:57 pm Post subject: Re: 300 Win Mag loads...

Friggin' weather...105* (no big deal) with 25-35 mph winds (very big deal)the past couple weekends, with more on the way.

Nice. Mad

slimjim · Posted: Thu Jul 08, 2010 4:41 pm Post subject: Re: 300 Win Mag loads...

I saw your shooting benches were under cover/shade. That's more than we get!

Are the winds that strong in the morning? Most times, I get up real early to be out on the range as soon as it opens even though its 75 miles away.

44marty · Posted: Thu Jul 08, 2010 8:05 pm Post subject: Re: 300 Win Mag loads...

stovepipe wrote:

Sierra wrote me back....super service!

Gave me some suggestions to try. Sent me a PDF for an accuracy load too using RE22. Not H4831...
They did have one listed for H4831 SC, not regular like I have.
Not sure if there's a burn rate diff or not. But max recomended there was 68.6gr.
70gr max for IMR 4831.
My OAL was on.
They also suggested trying to sneak up on the lands more too (Chambered?).

Glad I got this info before proceeding. They also want to hear back from me as I progress.
Great customer service!

Good stuff....

Stovey, I am guessing that the .300 Win mag will burn powder similar to a .300 WBY Mag (I could be wrong).
Did you get a chance to run these loads over a chronograph. I wasted a lot of rounds trying to figure out why some bullets wouldn't group with my WBY, before I got my chrono. It turned out that I was getting very inconsistent velocities with uncrimped loads. Crimped bullets got the powder to burn much more consistently.
Hornady has a good selection of .30 bullets with cannelures for crimping.

Also, as suggested in a few reloading manuals, slower-burning powders that most completely fill the case tend to give by far the best groups. RL-22 works great in the WBY.

slimjim · Posted: Fri Jul 09, 2010 5:20 am Post subject: Re: 300 Win Mag loads...

Crimping, a procedure I don't do because I don't use a press but looks like I should. I only neck size so haven't gone for adding another item to my work bench. I could use more consistency. When you crimp, do you have to flare the case open out before you reload the next bullet or is the crimp taken out during firing? Does crimping shorten your brass life?

stovepipe · Posted: Fri Jul 09, 2010 7:01 am Post subject: Re: 300 Win Mag loads...

Marty- goood advice. Using Match King bullets so there's no cannlure. Plus I'm single shooting it so... my pull weight is good with the 200gr bullet as the shank is huge, crimping is great for mag fed ammo.
No chrony though.

And yes- using a filling powder helps. 4831 does a pretty good job of that. Always room for improvement. Lots of powders and stuff to try and I've been eyeballing some of them Hornady bullets.

44marty · Posted: Fri Jul 09, 2010 10:22 am Post subject: Re: 300 Win Mag loads...

slimjim wrote:

Crimping, a procedure I don't do because I don't use a press but looks like I should. I only neck size so haven't gone for adding another item to my work bench. I could use more consistency. When you crimp, do you have to flare the case open out before you reload the next bullet or is the crimp taken out during firing? Does crimping shorten your brass life?

I keep reading in the manuals that crimped loads will have to be trimmed to length after fewer reloads than uncrimped, but I have NOT seen this with my brass.

Resizing the brass from crimped loads is no different than uncrimped (yes, the bullet takes out the crimp).

When I was getting poor groups from uncrimped rounds, I guessed that the problem was from my seating die. I bought a Forster bench-rest die, but it made no difference. It wasn't until I checked the velocity spread that I found out I was getting up to 800 fps variation with uncrimped, but only 30 fps or less variation from crimped rounds.

44marty · Posted: Fri Jul 09, 2010 10:39 am Post subject: Re: 300 Win Mag loads...

PS-
A couple of reloading manuals strongly recommend trimming all brass (even brand-new factory brass) to the "exact" same length before reloading, if you intend to use a crimp. This is suggested to make sure the crimp is the same for all rounds loaded.
I do not bother with this. I checked both bulk Remington brass, and Nosler custom brass, both fresh out of the box. They both varied about .005" (with a few of the Remingtons up to .008")
Bench-rest shooters usually trim all brass to length, ream the inside of case necks, and outside-turn the case necks as well. I have not seen any of them using a crimp - but then they don't usually shoot .300 Win Mag or WBY rounds.
Since I am getting groups well under 1" at 125 yards, I don't bother with any of this.

stovepipe · Posted: Fri Jul 09, 2010 10:58 am Post subject: Re: 300 Win Mag loads...

Good greif 800 fps difference is a ton!